Fix cache dir detection

[fd0]

This PR corrects a bug introduced just recently in the default cache dir detection for Darwin and Windows. It'll put the cache dir to ~/.cache instead of the correct location.

[codecov-io]

Codecov Report

Merging #1454 into master will decrease coverage by 0.18%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #1454      +/-   ##
==========================================
- Coverage    51.8%   51.61%   -0.19%     
==========================================
  Files         136      136              
  Lines       13760    13768       +8     
==========================================
- Hits         7128     7107      -21     
- Misses       5758     5792      +34     
+ Partials      874      869       -5

Impacted Files	Coverage Δ
internal/cache/dir.go	5.88% <0%> (-0.79%)	⬇️
internal/cache/cache.go	24.77% <0%> (-0.45%)	⬇️
internal/checker/checker.go	68.31% <0%> (-3.67%)	⬇️
internal/archiver/archiver.go	65.2% <0%> (-0.17%)	⬇️

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